Method of welding cylinder to head



Nov. 6, 1956 R. E. VAN DEVENTER 69,226

METHOD OF WELDING CYLINDER TO HEAD Original Filed April 24, 1950 INVENTOR. RALPH E. VAN DEVEMTER I! United States Patent C) IVIETHOD- OF WELDING CYLINDER T HEAD Ralph E. Van Deventer, Detroit, Mich., assignor to Studebaker-Packard Corporation, a corporation of Michigan.

Original application April 24, 1950, Serial-.No. 157,762. Divided and this application February 25,-;1-953,;Serial No.338,691

1 Claim. (Cl. 29 -156;-4)

It has long been common practice, in fabricating an internal combustion engine of relatively large size, to form the cylinder block by casting; andto'provide such block with cylindrical recessesfor thereception of cylinders which have been separately formed. It is.- also frequently found to be desirable to assemble together and unite into one integral structure, prior to'ernplacement' upon the cylinder block, the head and barrel of an individual cylinder assembly. Various proceduresfor the assembly in one integral structure of a cylinder. head and barrel have heretofore been proposed and made, use of in actual engine construction.

It is the purpose of the present invention to provide a head and barrel assembly of; novel and improved. character shown in my copending application Serial'No. 157,762 filed April 24, 1950, now abandoned an Particularly in this divisional application thereof to' provide a novel and improved process or method by means of; which the assembly of a cylinder head and associated barrel may be effected, to the end. that one integral structure, ready for assembly with the engine block, is realized.

By separately forming the head and-barrel'of a-cylinderit becomes easily possible for a manufacturer to employ, casting procedures in the formation of" the head and forging procedures in the formation of 'the barrel and also to use metals for these two parts: whichv vary somewhat in chemical composition and physical characteristics. Conveniently the head and: barrel-of such an assembly may beunited by. welding; and the present invention relates particularly to a cylinder head and barrel assembly in which these parts have been so united; and to a method for effecting thewelding operation' in a manner superior to' methods and procedures which have heretofore been suggested or utilized.

In the practice of the method the head and barrel are separately formed by methods chosen by the manufacturer to be most suitable. The head is provided with a peripheral flange with a cylindrical inner face and an annular end surface. The barrel is provided, at one end, with an annular end surface and an axially projecting portion which is adapted to slidably engage the cylindrical inner surface formed on the peripheral flange of the head. The arrangement is such that, when the projecting portion of the barrel is caused to telescope with the peripheral flange of the head, the head and barrel will be precisely in desired co-axial relationship, the annular end surfaces of the flange of the head and the end of the barrel are in mutually facing and equidistantly spaced relationship throughout, the projection from the barrel comprising a stop for limiting the movement of approach of head and barrel and likewise comprising means defining a cylindrical bottom for the groove or annular space intermediate the mutually facing end surfaces of head and barrel and into which space the weld metal is to be deposited.

After the assembly of head and barrel in this manner the annular groove as thus defined may be filled with weld metal by anyacceptable process of welding sothat': the head and barrel are rigidly united indesired'relae tionship. The projection which extends axiallyfrom the barrelend, which has served as' means forguiding and maintaining. the head and barrel of the cylinder into desired. relationship as. a pro-Welding operation, and: which has also served to. confine the molten weld metal during the welding operation, may then be 'cut away since it is no longer of utility and, as a matter of-"fa'ct',-. wouldtinterf'ere with or: limit the movement of thepiston unless removed. After removal of thiSl barrel projec' tion the interior of the assembly comprises a smooth cylindrical surface extending: from: end to end of the cylinder space, the innerface of" the. annular. band of Weld metal having: been rendered truly cylindricallduring the final machining operation involved in the removal of' the barrel projection and. being continuous: with the surfaces of the barrel below: it and: the inner cylindrical surface of the peripheral flange; abovev it. The: weld is: so. located that it cannot be reached". by any pistomring.

when the piston working in the barrel is at the top: of

its stroke,- although the piston stroke may be: of: such length thatv its upper end will pass beyond the weld; The resulting'assembly is of great: strength, and-:by. the method abovev briefly described it ispossible to 'ecornomicallyiconstruct lightweight but high qualityicylind'erhead and barrel assembliesquite: rapidly and, where'the" practice as described is employed, a high. quality low cost unit may be produced. I

Minor variations. in the procedure are: permissible; without departure from the invention. The process or. method may best be understood by reference to the accompanying drawings in which: are shown; rather diagrammatically, a cylinder head: and barreli ini the several positions which they relatively occupyv as: the processv is practiced.

In the drawings:

Figure 1 shows, inaxialisection and "co-axialirelationaship, portioni of' a. cylinder head and the adjacent end: of the cylinder barrel, these parts having beem fabricated: so asto have mutually telescoping, portionsand; being shown in the relative positions which they: occupy just? prior: to assembly; 7

Figure 2. shows a portion ofathe cylinder head' and a portion of the barrel justafter'as'sembly of these members; t

Figure 3 is a similar'view showingtheassembledtparts just aftercompletion ofithe welding operatibn;

Figure 4 is a further view of the same character, 2

showing the same portions of the assembly after removal of the barrel projection, which projection has completed its function; and

Figure 5 is an axial section through a completed cylinder barrel and head assembly, showing also small portions of the cylinder block upon which this assembly is mounted.

The head 10 of the cylinder may vary Widely in details of construction and may be fabricated in various ways provided, however, that it includes a peripheral flange such as indicated at 10a, this flange being generally cylindrical, having a cylindrical inner surface 10b the diameter of which is equal to the diameter of the finished cylinder, and an annular end surface the inner portion of which is frusto-conical. The cylinder barrel 11 is in the nature of a shell the wall of which is preferably thin and of high quality metal. At that end of the barrel which is to be attached to' the cylinder head it is provided with a frusto-conical end surface 11b and an inwardly offset projection which is preferably in the nature of a cylindrical extension of the barrel with a cylindrical outer surface 11d of substantially the same diameter as the cylindrical inner surface l P dhcwfi, 1956 b of the head 10, surface 11d being described about the axis of the inner cylindrical surface of cylinder 11 and being adapted to engage with a close sliding fit the cylindrical inner surface 10b of the head 10 when the peripheral flange 10a of the head and the cylindrical projection 110 of the barrel are telescoped., The tele scopingoperation will proceed until the parts occupy the relative positions in which they are shown in Figure 2, the projection 11c of the barrel being of such length as to limit the approaching movement of head and cylinder when the mutually facing annular surfaces 100 and 11b of the head and cylinder occupy the relative positions in which they are shown in Figure 2. A groove for the reception of weld metal is thus formed, this groove being defined by the frusto-conical surfaces 100, 11b and the exposed short portion or band of the outer cylindrical surface 11d of the projection 110 which lies between these surfaces. In cross section the groove is V-shaped and. is of such dimension as to facilitate welding.

Weld metal is then deposited in the resulting groove until a continuous band of weld metal 12 has been formed, rigidly uniting the mutually facing ends of flange 10a and barrel 11 and thus forming one integral structure of head and barrel. The barrel projection 110 is then removed by suitable machining operations, preferably followed by grinding until the cylindrical inner surfaces of the flange 10a of the head, the cylindrical inner surface of the band 12 of weld metal, and the cylindrical inner surface of the barrel 11 form one continuous smooth cylindrical surface. The assembled head and barrel are then ready for assembly with the block and may be so assembled, in the manner shown in Figure 5 or in any other suitable manner. The resulting structure is extremely strong and durable and the weld metal band 12, which comprises the sole connection between head and skirt, is, if the welding operation is properly carried out, at least as durable and long lasting as the members which it unites.

The operation just described may be practiced repeatedly with absolute uniformity of result, the resulting product is of the highest quality and the cost of production lower than comparable procedures heretofore or now practiced.

As previously explained the weld is so located, in the practice of the invention, that it may not be reached by any piston ring mounted upon the piston which is to work in the completed cylinder assembly, a piston in its uppermost position being indicated diagrammatically at 14 and piston ring at 14a. the surface of which the piston rings constantly move, is fabricated of metal best suited to resist wear and The barrel, over 5 is processed to provide maximum wear resisting properties, a nitralloy steel being particularly well suited for such use. The depth of the weld is equal to the width of the cylinder wall, a condition which ensures maximum strength. It will be understood that a step might be machined into the flange 10av and that the end of the flange 11c might abut this step instead of the undersurface of the head, without departure from the invention.

I claim:

The method of fabricating a one piece cylinder assembly defining a closed dome at one end of the combustion chamber for an internal combustion engine, which comprises the steps of forming upon the cylinder head an integral peripheral flange having an annular end surface spaced apart from the inside surface of the dome and having a cylindrical inner face disposed between the two said surfaces, forming a barrel with a cylindrical flange of predetemined length at one end offset inwardly from the inner wall of the body of the barrel and a transversely extending intermediate wall portion joining the barrel body and the cylindrical flange integrally together at that end, the wall portion presenting an annular end surface included between the respective junctures of the wall portion and each of the body of the barrel and the cylindrical flange thereof and maintaining the coaxial stepped relationship whereby the inner wall of the barrel body and the outer wall of the cylindrical flange are substantially longitudinally aligned, said cylindrical flange closely engaging the inwardly facing cylindrical surface of the flange of the head when it is inserted within said encircling flange to establish coaxial relationship between said head and the body of the barrel with the predetemined length to which the cylindrical flange is formed being such that when it is inserted into the encircling peripheral flange of the head it will, by abutting the dome in said head function as a stop limiting the extent of such insertion and accurately locating the mutual facing annular end surfaces of head and barrel in desired spaced relationship, filling the space between said annular end surfaces with weld metal to permanently unite the head and barrel, and thereafter cutting away the said cylindrical flange and the stepped transversely extending wall portion to provide a continuous cylindrical inner surface extending from the body of the barrel beyond the weld.

References Cited in the file of this patent UNITED STATES PATENTS 1,665,468 Murray Apr. 10, 1928 2,226,496 Jacocks Dec. 24, 1940 2,258,913 Stone Oct. 14, 1941 

